Artificial rubber like vulcanizates



bon,

Patented May 2, 1933' EDUAIRD TSCHUNKUR AND WALTER DOCK, OF COLOGNE-MUIHEIM, GERMANY, AS-

SIGNOBS TO I. G. FARBENINDUSTBIE AKTIENGESELLSCHAIFT,

or rmxronr-onrun-mam, GERMANY, A conrom'rron or onammr ARTIFICIAL RUBBER LIKE YULGAN'IZATES No Drawing. Application filed June 13, 1980, Serial No. 461,044, and in Germany Jnne 17, 1929.

The present invention relates to new artificial rubber-like vulcanizates derived from mixtures of natural rubber and artificial rub ber-like masses.

5 1 We have found that by vulcanizin mixtures of natural rubber varieties an artificial rubber-like masses, afterhaving' incorporated therewith a vulcanizing agent, such as sulfur, selenium, aromatic nitro' compounds +metaloxides' and the like, and finely divided carbon, more particularly carbon black, lamp black, oil soot or the like, with or without the addition of other filling materials, such as zinc oxide, coloidal silicic acid, etc., and furthermore, if desired, with the-addition of a vulcanization accelerator, plastifying agents or other materials known to favorably influence vulcanization processes, such as tar, oils, stearic acid, resins, etc., vulcanizates 0 are obtainable which in many cases are superior in their mechanical or other technically valuable properties to vulcanizates ob-' tainable in a similar manner from the constituent rubber or rubber-like materials of the mixtures.

The mixtures of natural rubber varieties with the artificial rubber like masses may be prepared in the most various manner. For example, a rubber-forming diolefine'hydocarmore particularly butadiene or a homologue or analogue thereof, such asisoprene, 2.3-dimethylbutadiene or the like, may be polymerized according to any desired polymerization process in the presence of natural rubber or latex. Suitable polymerization processes for this method of working are, for example, polymerization in the presence of an alkali metal, more particularly sodium metal, polymerization in emulsion with water and an' emulsifying agent or polymerization by simple heating, with or without the addition of. ingredients'known to favorably influence I such polymerization processes. Another method of preparing our mixtures of natural rubber and artificial rubber-like masses .is

by mechanically mixing these compounds, for.

example, on rollers or in a kneading machine. Furthermore, the constituents may in many cases be dissolved in rubber dissolving solvvents, such as benzene, ether, tetrachloromethane, ligroin and the like with the addition of finely divided carbon, other filling materials, vulcanizing agents, accelerators, etc., such solutions being suitable for impregnatmg purposes, yielding after vulcanization of the impregnated materials coating of technically valuable properties. The manufacture of th vulcanization mixtures from the solid natural rubber/artificial rubber like masses may be performed in the usual manner, for example, by rolling or kneading in the finely divided carbon (preferably in an amount between about 20-70% by weight of the rubber/rubber-like mass mixture) and other ingredients of the vulcanization mixture, and it may be mentioned that this rolling or kneading operation is easy to perform in view of th unexpected, great plasticity of the mixtures of natural rubber with artificial rubber-likemasses, which generally is substantially greater than that of the artificial rubber-like masses, which in many cases are workable on rollers or in-kneading machines only with diflic-ulty. It has already been proposed to overcome this difliculty by the addition of plastifying agents to the artificial rubber-like masses. But by these additions the mechanical properties of the vulcanizates generally are impaired, whereas our-mixtures yield vulcanizates of superior mechanical properties, amounting in most cases to a tensile strength between about 180 250 kg/sqcm at astretch between about 500 The vulcanization of the vulcanization mixtures as defined abovemay be performed in the usual manner, for example, by heating to about 100-140 C. for about -140 minutes, but it may be mentioned that these figures are in no way limitative, lower or higher temperatures, or shorter or 1onger times of vulcanization being operable in most cases. The vulcanizates thus obtainable may be used' for the manufacture of high grade tires, tubes, transporting bands, driving belts, surface coatings, stuffings and the like. Inmany. cases these fabrics are super or in their quality compared with those obtainable from only artificial rubber-like masses or naturalrubber, i. e. either by their mechanlcal properties or by their resistance to low temperatures, their resistance to the attack of chemical agents or their good rubbing properties.

The following examples illustrate our invention without limiting it thereto, the parts being by Weight.

Ewample 1 3 parts of sulfur, 15 parts of zinc oxide,

2 parts of tar, 2 parts of stearic acid, 50

parts of carbon black and 1 part of diphenyl-. guanidine are rolled into 10Qparts of a mixed rubber-like mass, containing 50 parts of artificial rubber, which mass has been obtained by polymerizing butadiene-(1.3) by simple heating to 6070 C. in the presence of natural rubber. The mixture is vulcanized at a temperature of about 130l40 C. in the usual manner. A high grade, elastic vulcanizate is thus obtained, possessing a tensile strength of 220-250 kg/sqcm ata stretch of 700750% and an elasticity of 48-50%.

' Example 2 65 parts of a rubber-like polyinerizate obtained by polymerizing butadiene in the presence of sodium metal are mixed by rolling or kneading with 35 parts of natural rubber, 70 parts of carbon black, 1 part of sulfur, 5 parts of zinc oxide, 4 parts of tar, 2 parts of stearic acid and 1.8 parts of a -60% alp Example 3 parts of a rubber-like mass, obtained by polymerizing a mixture of equal parts I H of butadiene-(L3) and 2.3-dimethylbutadiene-(1 .3) in emulsion with water and an emulsifying agent, 30 parts of natural rubber and the other ingredients, as outlined in Example 4 A tube is manufactured on a coronary press from a mixture consisting of 100 parts of a rubber-like mass obtained by polymerizing butadiene-(L3) in the presence of sodium metal and a diluting agent I l 100 parts of natural rubber I 80 parts of active gas soot 20 parts of inactive gas soot 5 parts of zinc oxide 10 parts of stearic acid 4 parts of sulfur 2 parts of a substance being able to protect rubber goods against deterioration due to age and 2 parts of a vulcanization accelerator. The mixture, in View of its great plasticity, is easily workable on the coronary press and the tube obtainable by-vulcanizing in the usual manner (t -140 O.) possesses good mechanical properties and good resistance to chemical agents.

Ewa'mplc 5 and The mixture is applied for impregnating purposes of the most various kind and the impregnated fabrics are Vulcanized in the usual manner.

Example 6 Into a mixture of 50 parts of butadienesodium rubber and 50 parts of natural rubber are rolled in and the mixture is calendered together with a linen strip and Vulcanized while pressin I Q by weight amma rub belts of very satisand( good resistance to rubtaine I mp 7 rubber-like mass obtained by factory stabili bing are thus '89 parts of a polymerizing 2.3-dimethylbutadiene in emul v sion. with water and an emulsifying agent, are: mixedon rollers or in a kneadm ma- {10 chine together with 39 parts of nature rubber, 3,15 parts of sulfur, 9,4 parts of zinc oxide, 1 part of tar, 1 part of stearic acid,

parts of carbon black and l'part of diphenylguanidine and the mixture is vulcanized at, n 136- C. for 50-70 minutes. The vulcanizates thus obtainable which are valuable for the manufacture of driving belts, transporting bands and the like, possess a tensile strengt ofl80-200 kg/sqcm at a stretch of 500-600%.

1. As a new product,.a rubber-like Vulcanizate com rising a mixture consisting of a butadiene iydroca'rbon lymerization product and of at least 10% b rubber, finely divided, carbon equal to between about to 70% of said mixture,

said vulcanizate generally possessing a tensile strength between about 180 to 250 kg/sqcm' at a stretch of about 500 to 800%.

' As a new product, a rubber-like vulcani'zate comprismg a mixture consisting of a polgyliiierized. hydrocarbon of the probable orm mow-Mm of between about to by welg natural rubber, a sootvariety of the consisting of carbon black, lamp ,bla oil soot in an amount 20 to 70% t of by weight of said mixture and sulfur, said vulcanizate generally possessing atensile between about 180 to 250 kg/sqcm at a stretch 3. As a new product, a rubber-like vulcanzate comprismg t, mixture consisting of an polymerizingbutadiene in the presence of i 60% by weight of natural rubber, a soot valampblack and oil soot in an amount equal to between about-20 to 70% by weight of said mlxture and sulfur, said vulcanizate generall a tensile strength. between a ut 180 to 50 kg/eqcm at a stretch of about'500 to 800%. I 4. As anew product, a rubber-like vulcanizate comprising] mixture consisting of an artificial merizing butadienedium" metal and of resence'ofsout25to60 ber,asootvariety in the between a lamp black and oil soot of about 600 to 700%.

y weight of natural and a 'vulcanizmg' agent, v

artificial rubber-like mass obtained by lkali'meta'l'and of between about 25 to rubber-like mass obtained by polyof the group consisting .of carbon in an amount ,0 to betweenabout 20 to 70% by weig t of said 'mixture and sulfur, said generall posse a tensile strength between a out 180 to 250 kg/sq m at a stretch of about 500 to 800%.

n 5. As a new product, a rubber-like vulcanizate comprisin arts by weight of a lymeriz ate o taina le by pol utadiene-(L3) in the presence of sodium metal, 35 and vulcanizate possessing a tensile between about 200 to 220 kg/sqcm at a stretch In testimony whereof, we aflix our signatures.

' EDUARDv TSC WALTER BOOK.

man amount by weight wherein X means hydrogen or methyl1,1 and equal to between about of. about 500 to 800%.

riety of thegroup consisting of carbon black,

parts .by weight of natural rubber parts by weight of carbon black said 

